retinal haemorrhages

A causative link between retinal haemorrhages and abusive head trauma is not universally accepted, but the identification, and documentation, of ocular abnormalities is a standard component of the examination of the injured child in life and in death.

Fundoscopy is a vital component of the medical evaluation of a living child suspected of having abusive head injury, whilst a gross, and microscopic, examination of the eyes at autopsy remains the current 'gold standard' for the evaluation of the dead child suspected of having been abused.

Could fundoscopy be used more frequently by pathologists, as well as opthalmologists, in the evaluation of the dead infant or child?

what is the significance of retinal haemorrhages in the eyes of infants and children?

Having identified, and documented, retinal haemorrhages, what can safely be said about their cause?

In addition to physical abuse - in which the specificity of retinal haemorrhages is controversial - retinal haemorrhages have been recognised in the setting of many natural disorders, including clotting disorders, childbirth, seizures, and infection (central nervous system and respiratory).

Some commentators, such as Tang et al (2008), consider the coexistence of retinal haemorrhages with subdural haemorrhage and cerebral oedema (in a setting of minimal external head trauma) - the so-called 'triad' - to 'virtually assure' a diagnosis of 'shaken baby syndrome'.

Gilliland and uthert (2003), however, consider it '... premature to consider that the eyes are in some way an independent arbiter of the mechanism or severity of injury'.

Bechtel et al (2004) suggested that retinal haemorrhages which were numerous, bilateral, multi-layered, and extended to the periphery/ ora serrata - or which were accompanied by perimacular folds - were more likely to be abusive in origin, although the specificity of these features has been questioned.

The cause of retinal haemorrhages in abusive head trauma is also controversial, and there are conflicting views as to whether they reflect local trauma, meningeal bleeding, or raised venous pressure.

The Royal College of Opthalmologists (UK), through its Child Abuse Working Party, advised that, 'in a child with retinal haemorrhages and subdural haemorrhages who has not sustained a high velocity injury and in whom other recognised causes of such haemorrhages have been excluded, child abuse is much the most likely explanation'.

systematic review of the literature

The Odds Ratio that a child with retinal haemorrhages has suffered abusive head trauma (non-accidental injury) is 14.7 (confidence interval 6.39, 33.62), and the probability of abuse is 91%.

Retinal haemorrhages in abusive head trauma are predominantly bilateral, numerous, and extend to the periphery.

Retinal haemorrhages are rare in non-abusive head trauma and are usually few in number, in the posterior pole, and only 10% extend to the periphery.

No one retinal finding is unique to abusive head trauma.

Having been a reviewer for that project, it was evident that much of the literature is based on single case reports, or groups of cases, and is of 'low quality'.

Additional potential limitations in the literature include a reliance on animal models and conflicting biomechanical data, and a lack of detail in the descriptions of the retinal findings.

At the very least, the presence of retinal haemorrhages must be considered an indicator for a thorough multi-disciplinary investigation into the circumstances of the child's injuries/ death.

A detailed medical examination must take place, including opthalomological examination, radiology (with 'skeletal surveys', and special views of long-bone metaphyses, and ribs), and pathology (including neuropathology, bone pathology, and opthalmic pathology).

The significance of the presence of retinal haemorrhages must then be considered together with all other investigations, in order to draw conclusions about the likelihood of abusive head injury in that particular case.

As to whether pathologists should be using fundoscopy in the mortuary, that would require some revision from days spent in clinical medicine but, if it is found to be a valuable screening technique, it might catch on.

Perhaps it might be safer, however, for opthalmologists to examine the eyes of all dead infants and children - where the cause of death is unknown, or suspicious - as soon as possible after death, as part of a standard protocol before that child is taken to the mortuary?